Overview
This lecture introduces the four major classes of biomolecules—carbohydrates, lipids, proteins, and nucleic acids—emphasizing their monomers, functions, and importance in cell structure and life.
Biomolecule Classes & Their Monomers
- There are four major biomolecule classes: carbohydrates, lipids, proteins, and nucleic acids.
- Biomolecules are large molecules (macromolecules) essential for life.
- Monomers are the building blocks of these macromolecules.
Carbohydrates
- Carbohydrates are found in foods like bread, pasta, fruits, and vegetables.
- The monomer of carbohydrates is the monosaccharide (e.g., glucose).
- Two monosaccharides form a disaccharide (e.g., maltose); many form a polysaccharide (e.g., starch).
- Carbohydrates provide fast energy, are involved in energy storage (starch in plants, glycogen in animals), and form cell structures (cellulose in plants, chitin in fungi).
Lipids
- Lipids include fats, oils, phospholipids, triglycerides, and steroids.
- Building blocks of most lipids are glycerol and fatty acids.
- Lipids are hydrophobic and do not dissolve in water.
- Functions: long-term energy storage, form cell membranes (phospholipid bilayer), provide insulation, and act as hormones.
Proteins
- Protein food sources include beans, meat, nuts, and eggs.
- Proteins are made of amino acid monomers.
- Proteins provide structural support (muscle, hair, collagen), function as enzymes, antibodies, hormones, and membrane channels/receptors.
Nucleic Acids
- Nucleic acids include DNA and RNA, with nucleotide monomers.
- Found in all living things (plants, animals, bacteria, fungi).
- Store and transmit genetic information necessary for coding traits and cellular functions.
Major Elements in Biomolecules
- Major elements: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous (mnemonic: CHO, CHO, CHON, CHONP).
- Arrangement of these elements determines biomolecule structure and function.
Key Terms & Definitions
- Biomolecule — Large molecule needed for life, also called macromolecule.
- Monomer — Building block of a macromolecule.
- Monosaccharide — Simple sugar, monomer of carbohydrates.
- Polysaccharide — Multiple monosaccharides linked together.
- Hydrophobic — Repels water; characteristic of most lipids.
- Amino Acid — Monomer of proteins.
- Nucleotide — Monomer of nucleic acids.
- Enzyme — Protein that speeds up chemical reactions.
- Hormone — Chemical messenger for bodily processes.
Action Items / Next Steps
- Review further reading in the provided description about biomolecule structure and function.